Engine ignition timer with improved adjustable plates

ABSTRACT

The position of the breaker contacts with respect to the timing cam is adjusted by providing a worm gear set for adjustably rotating the breaker contact carrying plate.

United States Patent Wickman June 27, 1972 1 1 ENGINE IGNITION TIMER WITH IMIROVI'II) ADJUSTABLE PLATES 172| Inventor: Vernon C. Wickman, Milwaukee, Wis.

17]] Assignce: AMF Incorporated 122] Filed: Jan. 4, 1971 [21] Appl. No.: 103,499

[52] US. Cl. ....200/19 R, 200/31 [51] Int. Cl. ..H0lh 19/00 [58] Fleld otSearch ..200/l9 R, 19 A,21,22,25, 200/29, 31

[56] References Cited UNITED STATES PATENTS 2,048,860 7/1936 Guziel et al ..200/21 2,773,141 12/1956 Baker ..200/31 3 342,274 3/1966 Sanden ..200/31 3,319.018 5/1967 Hubbard ..200/31 3,434,027 3/1969 Cummings e ..200/31 3,51 1.945 5/1970 Chambers ..200/31 Primary Examiner-J. R. Scott Attorney-George W. Price and Walter Lewis ABSTRACT The position of the breaker contacts with respect to the timing cam is adjusted by providing a worm gear set for adjustably rotating the breaker contact carrying plate 3 Claims, 4 Drawing Figures ENGINE IGNITION TIMER WITH IMPROVED ADJUSTABLE PLATES This invention relates to an ignition timer, and more particularly, to an improvement in adjusting the timing of an ignition timer for an internal combustion engine.

It is an object of this invention to provide an improved and low cost adjusting mechanism for the timing of an engine ignition system.

The invention is illustrated in connection with the ignition timer for a two cylinder V-engine for a motorcycle, but is not necessarily restricted thereto. Briefly, in the invention the circuit breaker housing has a circular plate mounted therein. The plate is adapted to have a pair of breaker contacts mounted thereon and is centrally apertured so that the timing cam protrudes therethrough adjacent to the contacts. The plate is nested in the housing so that it can be manually rotated with res ect to the timing cam. Adjustment of the plate, that is to say its breaker contacts, with respect to the timing cam is accomplished by a worm gear set for the plate. The worm gear set comprises gear teeth formed on a portion of the outer edge of the plate and a threaded stud or bolt which is mounted in the housing and tangentially disposed with respect to the toothed plate portion to operate as a pinion thereon.

The features of the invention which are believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a top view of an engine circuit breaker with cover cap removed;

FIG. 2 is a sectional view taken along the line 22 of FIG.

FIG. 3 is an electric circuit diagram of the ignition system; and

FIG. 4 is a sectional view taken along the line 4-4 of FIG. I.

Referring now particularly to the single sheet of drawing, shown therein is a circuit breaker housing I having a pair of plates 1 I and 12 mounted therein. As a practical matter these plates are identical, and are positioned one on top of the other in perpendicular relationship with respect to the lengthwise axis of the housing. The housing is adapted to be closed by a cover cap I3.

Each plate has a central cut out 14 so that they are really annular in shape with an inner radial ledge 15. The plates are shifted with respect to each other so that their ledges 15 are positioned across from each other. The ledges 15 are adapted to have the breaker contacts for different cylinders mounted thereon.

The ignition system consists of two ignition coils I6, two contact breakers I7, two spark plugs I8, two capacitors 19, an ignition switch 20, and a battery 21. The current from the battery 2I flows through the ignition coil 16 and the circuit is completed by grounding through the contact breaker I9. One of the breakers furnishes high voltage current to one spark plug, and the other breaker furnishes the current to the other spark plug. The purpose of the capacitors I9 is to prevent unwanted sparking across the points of the contact breakers. The contact breakers I7 are mounted by not shown brackets on the ledges I5 of the separate plates II and 12 in a manner well known to those skilled in the art and as is done in the double contact breaker used in motorcycles currently manufactured by Harley-Davidson Motor Co., Inc., a subsidiary of the assignee of the instant invention.

The plates 11 and 12 are nested in the housing I0 on a shoulder 22. Superposed on the plates 11 and I2 is a spring washer 23 and a split lock washer 24 which is received in a groove 25 formed in the housing ID.

The breaker contacts I7 are operated to open position by a timing cam 26 which is positioned between the two ledges or inner radial protuberances I5 formed on plates 11 and 12. Timing cam 26 is operated by a shafi 27 which is operated in synchronism with the engine crankshaft.

The worm gear set for each plate 11 and 12 comprises gear teeth II and 12' formed on the plates II and I2 respectively and threaded studs or bolts II" and 12" which operate as pinions for the gear teeth II and 12 respectively. The bolts I1" and 12'' are rotatably mounted in enlargements 28 formed in the housing 10 and are disposed tangentially with respect to the gear wheel teeth 11' and 12'. The teeth II are shown as being integral with the plate II, but they can be separately formed and then attached thereto as shown by the attachment of the gear teeth 12' to the plate 12.

The right hand stud II" is shown as being held in position in the enlargement 28 by a lock washer 29 which is snapped into a groove cut in that end of the stud. However, another way of holding the stud in position is like that shown by the left hand stud 12" which uses a more conventional lock washer 30 and nut 31. Both studs 11" and 12" have grooved heads which are adapted to receive the point of a screw driver for manually adjusting the position of plates 11 and I2 separately with respect to the timing cam 26.

It will now be seen that with a selection of fine teeth for the worm gear sets micro-adjustments can be made very easily merely with a screw driver. In addition, once the adjustment is made it is set since parts II" and 12" can move the parts II and I2 whereas the reverse isn't true.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and that it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In an engine ignition circuit breaker comprising a housing having breaker contacts mounted therein and a timing cam for operating said contacts, and means for adjusting the relative position of said contacts and cam, the improvement of said means comprising two circular plates rotatably nested in said housing in perpendicular relationship with the axis thereof, said plates being adapted to have said contacts mounted thereon, a gear segment on said plates, and two pinion members mounted on said housing and in engagement with said gear segments for separately rotating said plates relative said cam,

wherein said plates are nested in said housing one above the other, said plates being annular in shape and each having an integral radially inner extending portion thereon for mounting breaker contacts thereon, said plates being aligned relative to each other to place their radial portions across from each other, and said cam being positioned between said radial portions.

2. In a circuit breaker as in claim I, wherein said gear segments are formed along the outer circumferential edge of said plates, and said pinion members being rotatably mounted in integral enlargements of said housing in tangential relationship to said plates in engagement with said gear segments with said gear segments.

3. In a circuit breaker as in claim 2, said enlargements, gear segments, and pinion members being positioned along opposite sides of said housing, said plates having similar configurations and being interchangeable, and said pinion members comprising screw driver operated threaded studs.

i I i i i 

1. In an engine ignition circuit breaker comprising a housing having breaker contacts mounted therein and a timing cam for operating said contacts, and means for adjusting the relative position of said contacts and cam, the improvement of said means comprising two circular plates rotatably nested in said housing in perpendicular relationship with the axis thereof, said plates being adapted to have said contacts mounted thereon, a gear segment on said plates, and two pinion members mounted on said housing and in engagement with said gear segments for separately rotating said plates relative said cam, wherein said plates are nested in said housing one above the other, said plates being annular in shape and each having an integral radially inner extending portion thereon for mounting breaker contacts thereon, said plates being aligned relative to each other to place their radial portions across from each other, and said cam being positioned between said radial portions.
 2. In a circuit breaker as in claim 1, wherein said gear segments are formed along the outer circumferential edge of said plates, and said pinion members being rotatably mounted in integral enlargements of said housing in tangential relationship to said plates in engagement with said gear segmenTs with said gear segments.
 3. In a circuit breaker as in claim 2, said enlargements, gear segments, and pinion members being positioned along opposite sides of said housing, said plates having similar configurations and being interchangeable, and said pinion members comprising screw driver operated threaded studs. 